Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH301:11

ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

7.5K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
7.5K
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H01:13

meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H

6.7K
All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for...
6.7K
2° Amines to N-Nitrosamines: Reaction with NaNO201:20

2° Amines to N-Nitrosamines: Reaction with NaNO2

5.5K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
5.5K
SN2 Reaction: Kinetics02:14

SN2 Reaction: Kinetics

10.3K
Kinetic Studies and Significance
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
10.3K
SN2 Reaction: Mechanism02:27

SN2 Reaction: Mechanism

17.5K
The kinetic studies of SN2 reactions suggest an essential feature of its mechanism: it is a single-step process without intermediates. Here, both the nucleophile and the substrate participate in the rate-determining step.
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
17.5K
SN2 Reaction: Transition State02:26

SN2 Reaction: Transition State

12.0K
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
12.0K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Dynamic Self-Healing Polymer Architectures for High-Performance Flexible Sensing.

Advanced materials (Deerfield Beach, Fla.)·2026
Same author

Moisture-Gated Synergistic Rapid Crystal-to-Liquid Transition in Pyridinium Halide Crystals via [2 + 2] Photocycloaddition.

Small (Weinheim an der Bergstrasse, Germany)·2026
Same author

A Closed-Loop Recyclable Hydrogel With Temperature-Programmable Photomorphing Enabled by a Dynamic Spiropyran-Disulfide Network.

ChemSusChem·2026
Same author

Biomimetic Supramolecular Assemblies With Programmable Structural and Chiroptical Dynamics.

Angewandte Chemie (International ed. in English)·2026
Same author

Supramolecular polymerization couples constitutional adaptability and fluorescence response in a dynamic covalent library.

Chemical communications (Cambridge, England)·2026
Same author

Aspect ratio-dependent twisting motions in photomechanical molecular crystal ribbons <i>via</i> solid-state [2+2] photodimerization.

Chemical communications (Cambridge, England)·2026
Same journal

The role of spacer length and flexibility in peptide self-assembly.

Beilstein journal of organic chemistry·2026
Same journal

Novel macrocycles: from synthesis to supramolecular function.

Beilstein journal of organic chemistry·2026
Same journal

Electrochemical reduction of unsaturated carbon-carbon bonds via 3d transition-metal catalysis.

Beilstein journal of organic chemistry·2026
Same journal

Synthesis of sterically shielded piperidine nitroxides via acid-catalyzed heterocyclization of β-aminoketone derivatives with ketones.

Beilstein journal of organic chemistry·2026
Same journal

Chiral cyclopropenimine-catalyzed enantioselective Michael reactions of phenol and benzofuran-derived α,β-unsaturated pyrazolamides with benzophenone-imine of glycine esters.

Beilstein journal of organic chemistry·2026
Same journal

A practical CO<sub>2</sub>-mediated synthesis of 5,6-carboxylated silicon-rhodamines for targeted probe development.

Beilstein journal of organic chemistry·2026
See all related articles

Related Experiment Video

Updated: Feb 5, 2026

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging
10:17

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging

Published on: June 26, 2017

12.5K

A switchable [2]rotaxane with two active alkenyl groups.

Xiu-Li Zheng1, Rong-Rong Tao1, Rui-Rui Gu1

  • 1Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.

Beilstein Journal of Organic Chemistry
|September 12, 2018
PubMed
Summary
This summary is machine-generated.

Researchers developed a novel functional [2]rotaxane with alkenyl bonds, enabling reactions with various groups. Its macrocycle movement, controlled by acid and base, creates a platform for stimuli-responsive polymers.

Keywords:
alkenyl bondfunctional crown etherstimuli-responsivenessswitchable rotaxane

More Related Videos

Ex Vivo Analysis of Mechanically Activated Ca2+ Transients in Urothelial Cells
05:35

Ex Vivo Analysis of Mechanically Activated Ca2+ Transients in Urothelial Cells

Published on: September 28, 2022

1.4K
Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition
12:47

Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

Published on: May 2, 2014

22.2K

Related Experiment Videos

Last Updated: Feb 5, 2026

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging
10:17

Switchable Acoustic and Optical Resolution Photoacoustic Microscopy for In Vivo Small-animal Blood Vasculature Imaging

Published on: June 26, 2017

12.5K
Ex Vivo Analysis of Mechanically Activated Ca2+ Transients in Urothelial Cells
05:35

Ex Vivo Analysis of Mechanically Activated Ca2+ Transients in Urothelial Cells

Published on: September 28, 2022

1.4K
Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition
12:47

Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

Published on: May 2, 2014

22.2K

Area of Science:

  • Supramolecular Chemistry
  • Polymer Science

Background:

  • Rotaxanes are mechanically interlocked molecules with potential applications in molecular machines and responsive materials.
  • Functional groups on rotaxanes can enable specific chemical reactions and stimuli-responsiveness.

Purpose of the Study:

  • To design and synthesize a novel functional [2]rotaxane incorporating alkenyl bonds.
  • To investigate the reactivity and stimuli-responsive properties of the synthesized rotaxane.

Main Methods:

  • Synthesis of the functional [2]rotaxane.
  • Characterization using 1H, 13C NMR spectroscopy.
  • Characterization using High-Resolution Electrospray Ionization mass spectrometry (HRESI mass spectrometry).

Main Results:

  • Successful design and synthesis of a novel functional [2]rotaxane with two alkenyl bonds.
  • Demonstrated reactivity of the rotaxane with alkenyl and thiol functional groups.
  • Observed reversible shuttling of the macrocycle between recognition sites, controllable by external acid and base.

Conclusions:

  • The novel functional [2]rotaxane serves as a versatile platform for chemical modifications.
  • The stimuli-responsive nature of the rotaxane's shuttling movement is confirmed.
  • This work provides a foundation for developing advanced stimuli-responsive polymers.